Does anyone know the forging temp range of 932 bearing bronze?

Joseph Bandeko

Joseph Bandeko

Knifemaker / Craftsman / Service Provider
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I’m ordering some 932 bearing bronze and would like to try forging it, does anyone know the forging temps for this type of bronze? I know that some types can’t really be forged at all, is 932 one of them?
 
Generally speaking, you don't forge brass or bronze hot. You do it at room temp. When it starts to get harder to hammer, heat it up red hot, then quench it in water to soften it.
 
Well I might end up doing that method but would prefer to forge hot if I can, and I know it can be done with other bronze grades, just not sure about 932
 
932 is a bearing bronze. It isn't forgeable and isn't what you want for knife blades or hardware. It is a high lead/tin bronze. It is 83% copper, and the rest is lead/tin/zinc.
Pick a different alloy. Naval bronze (it is properly called naval brass) is your best choice. Forging brass #C37700 is just a tad better, but harder to come by. If you want a true bronze, then Architectural bronze would be the most forgeable.

All that said, the way to forge bronze, brass, or copper is to anneal it and work it warm to cold (below 500°F). Heat to a dull red (900-1000°F) and quench in water. That softens it. Forge until you feel it stiffening and resisting malleation. Re-anneal and continue. You can repeat this hundreds of times if needed.

Forging bronze hot has a very shallow range - 500-900°F. If outside that range the metal will either crumble or crack. Cold forging annealed bronze/brass below 500°F is simple and easy.
 
Well it’s already on it’s way...
So I can only cold forge the bearing bronze.
The piece I ordered is round and I would just want to ”forge” it into a rectangle, I’ll be using it for knife guards. is the lead in it going to be a hazard, both grinding and In the final product, say around food and such? if the lead is going to be a hazard then I’ll return it, if not then I’ll just work with it.
 
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932 is 7% lead and 7% tin. That is a significant amount.
I doubt you will successfully forge it to a rectangle without some issues, but it will have to be done by cold forging. Don't let it get beyond the barest red color or it will start to crumble. I would suggest 1000°F as the max temperature in annealing.

Also, I think it won't look pretty as a guard.
 
OK, I’m going to return the 932 and get some 655 silicone bronze instead.
Thank you guys for your help.
 
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Now that you can forge.
655 is 97% copper and 3% silicon. It will hot forge, but it has to be done at a low red color.
Work it between 1300 and 1600°F. If you get it any hotter it will smush apart.
Anneal at 900-1300°F.
When hot forging, once it loses all color, re-heat to red and forge on. Final detail forging is best done annealed and below 900°F. Cold forging is fine for the final details.
 
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